A telecommunications switch is used to route message traffic over a network. Usually it comprises a chassis or housing containing circuitry on a multiplicity of printed circuit cards which plug into a motherboard in the chassis. The various communications lines are plugged into connectors on those cards, the connectors being exposed at openings in the back of the chassis. The actual switching may be controlled by a central processor unit (CPA) on the motherboard in accordance with programs and instructions provided from disc drives in the chassis or from an external keyboard. The chassis usually also contains a power supply for supplying power to the various parts of the switch.
Many present clay switch chassis and housings are disadvantaged in that they are relatively complicated to assemble. Also, their interiors are not organized to facilitate the installation and servicing of the various parts which make up the switch such as printed circuit cards, disc drives, cooling fans, etc. Furthermore, the interior layouts of the chassis are not very flexible in that they do not take into account the fact that some switches may require more or different memory storage than others, or some may need a DC power supply rather than an AC supply or redundant supplies.
Another area which is not addressed sufficiently by prior switch chassis constructions is accessibility both in terms of security and personal safety. In many cases, parts of the switch which have to be reached for routine replacement or repair, the low voltage PC-AT cards for example, are located near disk drives which may carry sensitive information or near dangerous high voltage power supplies.
What is needed, then, is a switch chassis design which takes all of these things into consideration, yet is manufacturable at a reasonable cost.